1. Field of the Invention
The invention relates to a storage system, and more particularly to a technique for partitioning resources in a storage system into logical partitions.
2. Description of Related Art
Recently, the need for storage consolidation aimed at reducing the cost of installation or management of storage systems has been increasing more and more. It is expected that from now on, data owned by several separate departments or companies will be stored in a single storage system by utilizing storage consolidation technology. In that case, a technique for enabling provision of a single storage system as plural virtual storage systems, and more particularly a logical partition technique for storage systems, is necessary for preventing management or performance interference in a single storage system. A method for statically allocating IO (Input/Output) performance (data transfer performance or transaction processing performance) or cache capacity when setting logical partitions in a storage system has been proposed (JP-A-2006-244098).
In the above mentioned technique, the allocation amount is changed when setting logical partitions in a storage system. However, when doing so, it is necessary to determine a schedule in advance, or input a special command from a host computer, and therefore it is difficult to change the amount of allocated resources dynamically when the storage system is online. Therefore, the maximum amount of resources which can be used, such as IO performance and cache capacity, that would be required has to be allocated from the beginning. In other words, the maximum amount of resources required has to be allocated to each logical partition even if there is a possibility that the system will be modified from its initial state or that the load from the host computer will change. As a whole, resources allocated, but not in use, may not be able to be used effectively.
An object of the invention is to dynamically change the amount of allocated resources in a storage system.